General Properties
Short Name:
Name:
PEI
Polyetherimide
Polyetherimide (PEI) is a high temperature-resistant high-performance thermoplastic. It is transparent and has a golden yellow color.
Structural Formula
Properties
| Glass Transition Temperature | 215 to 230°C |
|---|---|
| Melting Temperature | - |
| Melting Enthalpy | - |
| Decomposition Temperature | 540 to 550°C |
| Young's Modulus | 2900 to 3000 MPa |
| Coefficient of Linear Thermal Expansion | 50 *10-6/K |
| Specific Heat Capacity | - |
| Thermal Conductivity | 0.22 W/(m*K) |
| Density | 1.27 g/cm³ |
| Morphology | Amorphous |
| General properties | High stability. High electrical impact strength. Good hydrolysis resistance. High UV and gamma ray resistance. Good resistance to stress cracking. Self-extinguishing |
| Processing | Injection molding, injection blow molding, extrusion, foaming |
| Applications | Electrics/electronics (e.g., housings, circuit boards). Aircraft construction (e.g., panels, coatings). Automobile industry. Medical engineering. Instrument and apparatus engineering |
NETZSCH Measurement
| Instrument | DSC 204 F1 Phoenix® |
| Sample Mass | 11.53 mg |
| Isothermal Phase | 3 min / 3 min / 5 min |
| Heating/Colling Rates | 10 K/min |
| Crucible | Al, pierced lid |
| Atmosphere | N2 (40 ml/min) |
Evaluation
Polyetherimide (PEI) is completely amorphous and belongs to the high-temperature plastics, as reflected by the high glass transition temperature of approx. 217°C in the 2nd heating (red, midpoint) and 215°C in the 1st heating (blue). The glass transition in the 2nd heating is overlapped with a small RelaxationWhen a constant strain is applied to a rubber compound, the force necessary to maintain that strain is not constant but decreases with time; this behavior is known as stress relaxation. The process responsible for stress relaxation can be physical or chemical, and under normal conditions, both will occur at the same time. relaxation peak. The controlled cooling at 10 K/min was probably far slower than the cooling rate employed during production of the polymer, causing the short-range order that was responsible for the endothermal RelaxationWhen a constant strain is applied to a rubber compound, the force necessary to maintain that strain is not constant but decreases with time; this behavior is known as stress relaxation. The process responsible for stress relaxation can be physical or chemical, and under normal conditions, both will occur at the same time. relaxation peak.